Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain , Croix du Sud 1 (L7.04.01), 1348 Louvain-la-Neuve, Belgium.
Langmuir. 2014 Jan 14;30(1):268-77. doi: 10.1021/la403891k. Epub 2013 Dec 24.
The conformation of polymer chains grafted on a substrate influences protein adsorption. In a previous study, adsorption/desorption of albumin was demonstrated on mixed poly(ethylene oxide) (PEO)/poly(acrylic acid) (PAA) brushes, triggered by solutions of adequate pH and ionic strength (I). In the present work, homolayers of PEO or PAA are submitted to saline solutions with pH from 3 to 9 and I from 10(-5) to 10(-1) M, and their conformation is evaluated in real time using quartz crystal microbalance with dissipation monitoring (QCM-D). Shrinkage/swelling of PAA chains and hydration and salt condensation in the brush are evidenced. The adsorption of human serum albumin (HSA) onto such brushes is also monitored in these different saline solutions, leading to a deep understanding of the influence of polymer chain conformation, modulated by pH and I, on protein adsorption. A detailed model of the conformation of PEO/PAA mixed brushes depending on pH and I is then proposed, providing a rationale for the identification of conditions for the successive adsorption and desorption of proteins on such mixed brushes. The adsorption/desorption of albumin on PEO/PAA is demonstrated using QCM-D.
接枝在基底上的聚合物链的构象会影响蛋白质的吸附。在之前的研究中，通过适当 pH 值和离子强度 (I) 的溶液，证明了混合聚环氧乙烷 (PEO)/聚丙烯酸 (PAA) 刷上白蛋白的吸附/解吸。在本工作中，PEO 或 PAA 的均聚物层经受 pH 值为 3 至 9 和 I 值为 10(-5) 至 10(-1) M 的盐溶液，并使用石英晶体微天平实时监测其构象（QCM-D）。证明了 PAA 链的收缩/溶胀以及刷层中的水合和盐凝结。还在这些不同的盐溶液中监测了人血清白蛋白 (HSA) 对这些刷的吸附，从而深入了解了由 pH 值和 I 值调节的聚合物链构象对蛋白质吸附的影响。然后提出了一个 PEO/PAA 混合刷构象随 pH 值和 I 值变化的详细模型，为在这种混合刷上连续吸附和解吸蛋白质的条件的识别提供了依据。使用 QCM-D 证明了白蛋白在 PEO/PAA 上的吸附/解吸。
